Dissolving urea

[Oldmacdonald]

I do it on a small scale. My bags of urea in Ireland are 375kg. I have ibc tank with big hole cut in top. Cut open bag into tank. Top up with water so it's approximately 1000 litres of of solution. And drop a 2 inch submersible pump in.

How long does that take to dissolve?

 

[Against_the_grain]

What are the advantages of dissolving your own rather than just buying it in liquid form ?
Thanks

Cost.
Basically I'm getting most of the advantages of liquid but at Urea prices.

 

[Farmer Roy]

For the curious, this is the maths for the energy needed to dissolve urea; the numbers are pretty big.
From what I can gather from deciphering the 'American units' the water temperature would need to be about 50 celsius to completely dissolve the urea instantaneously. On farm it's always done at ambient temperature, so the length of time will depend on the air temp, the amount of sun reaching the tank, tank colour etc. The tank temperature drops to about -8.5C, and as per the above pictures the outside of the tank will frost over at anything under about 15C air temp. We've tried heating the underside of the tank at 100C using a canvas 'skirt' and a big diesel space heater, but it caused the urea to form a hard enamel like layer on the bottom of the tank. The more efficient way would be to heat the water first, but your as well starting the reaction quicker without extra heat and saving the extra hassle.

a quick & easy way to cool your beers down is to put some urea in a bucket, add water & drop your beers into it

 

[czechmate]

I used to be doing this in the uk to use as a “protein boost “ on milling wheat.
i was never sure if it actually increased the wheat protein… or just tricked the measurements?
can anyone clarify ? As for my own use, it would be useful to have genuinely higher protein wheat (used for my own animal feed)

 

[e3120]

I used to be doing this in the uk to use as a “protein boost “ on milling wheat.
i was never sure if it actually increased the wheat protein… or just tricked the measurements?
can anyone clarify ? As for my own use, it would be useful to have genuinely higher protein wheat (used for my own animal feed)

You could argue that even the 'tricked' version would be just as good for feeding, although it takes a little dietary energy to synthesise the urea into protein. That's assuming you weren't already maxing out the protein contribution from urea. My man recommends no more than 2% of the protein that way. You have to be eagle-eyed on how the protein of bought-in feeds is achieved (especially liquids), as urea is a very cost effective way, even at the heights.

 

[Andrew K]

We have been using a higher capacity [1300LPM] pump this year and are seeing an average reduction in mixing time and faster tank unloading of around 20% in time terms.
Other customers are saying similar things.

 

[PSQ]

We have been using a higher capacity [1300LPM] pump this year and are seeing an average reduction in mixing time and faster tank unloading of around 20% in time terms.
Other customers are saying similar things.

Pictures and details please.

The pump you sold me in 2016 is starting to look like it's been used to make a million litres of fertiliser...

 

[Blue.]

Agitation is your friend, helped along by a decent pump. We use a 16,000L tank with a 400L/minute pump (2”) feeding 5 ‘eductors’ (Venturi jets) bought on 'Alibaba' of all places.

View attachment 1107190
View attachment 1107189

Have you got weigh cells on the tank?

 

[PSQ]

Have you got weigh cells on the tank?

No, it's the digital display for the weigh bridge, it comes in handy for measuring out ammonium sulphate for UAS mixes.
The bits that look like cells are inch plate squares to stop it falling through the concrete as it weighs 26t when full, and 7t empty (22mm thick steel).

 

[snarling bee]

Cost.
Basically I'm getting most of the advantages of liquid but at Urea prices.

How much does it cost for the energy to mix, depreciation on the tank, carting around a lot of bulk and the time factor??

 

[robin banks]

How long does that take to dissolve?

Back in February I would put a mix on at 5pm and it would be left all night and be mixed next morning. That was cold water from well

 

[Chickcatcher]

Back in February I would put a mix on at 5pm and it would be left all night and be mixed next morning. That was cold water from well

Morning Robin. were you above, pumping it from 5pm.
Would it dissolve if just left in the tank for a month say? Got some Urea left and going to last dose using Liquid ear wash if you were to be intending to put lets say 30kgHa on at this time having mixed it as previously said @1550Lts to 1000kG of Urea@46% would it be 155Lts/ha ( I am thinking you would end up with more than 1550Lts when the urea is added) I am thinking there must be best part of 2000+Lts from the above product mix.

 

[Farmer Roy]

Place I used to work on, not far from home, used to mix all their N fert, on a 4000 acre irrigation farm
Had boat propellers driven by electric motors to agitate the mix, rather than pumps. Pumps only used to fill & empty the vats

mixed SA ( back when we could buy it ) & urea “fines”, which he bought direct from the BHP steelworks in Newcastle.
Can’t do that anymore either . . .

 

[robin banks]

Morning Robin. where you above, pumping it from 5pm.
Would it dissolve if just left in the tank for a month say? Got some Urea left and going to last dose using Liquid ear wash if you were to be intending to put lets say 30kgHa on at this time having mixed it as previously said @1550Lts to 1000kG of Urea@46% would it be 155Lts/ha ( I am thinking you would end up with more than 1550Lts when the urea is added) I am thinking there must be best part of 2000+Lts from the above product mix.

Does not dissolve with out agitation. I sometimes have 3 tanks to mix. What I would do there is put the pump in 1 for 20 or 30 minutes then move it to the other and so on. And then leave it in first one over night. That initial mix gets things going. Then next day the mix is probably half dissolved and water warmed up again in the 2 tanks that got a small agitation. Then next morning it does not take too long to get it mixed. All times are just guesses. But I have left urea for few days in water and doesn't dissolve on its own.
Others will know formula for urea quantity but roughly it's 1.3kg per litre so by my math you have 1950 litres from your mix.
I don't bother too much about specific gravity as I work on volume of mix. If I put in 375kg of urea and I end up with 1000 litres or 950 litres in my sprayer tank I know I have 375kg of urea and work out my rate as such. It's not complicated when you look at it that way.

 

[Hard Graft]

Pumps are very energy intensive compared to mixing Impellers in the tank a round tank like @PSQ is ideal and is what I am looking for

 

[Blue.]

I’ve a spare 5000 litre milk tank with a paddle,would that move it enough?

 

[Hard Graft]

I’ve a spare 5000 litre milk tank with a paddle,would that move it enough?

It’s slower due to the insulation and don’t go adding all the urea in one go for a 20N mix as I had the urea stop the paddle. Add overload protection to the motor as it’s alot cheaper than a motor and gear box. (Talking form experiencethough it’s cheep to run as the motor size and the odd time I have to add mixing with the pump

Ps ignore the mess

 

[PSQ]

Pumps are very energy intensive compared to mixing Impellers in the tank a round tank like @PSQ is ideal and is what I am looking for

Pumps are surprisingly efficient, and simple to engineer into any system. The current 2” Pacer pump is something like 3.5hp, so will be about 2.6kW/h, or about 65p an hour on an average 25p/kWh tariff. Say 20 hours of pumping per 15,000L batch (I turn it off before bed), totals £13 or less than £1 per cube. Please check the maths, I may be wrong.
One thing to note is to use ‘eductors’ (venturis) which increase the volume of pumped water by a factor of 5, so 400L/minute from the pump moves more like 2000L of solution.

 

[Hard Graft]

Pumps are surprisingly efficient, and simple to engineer into any system. The current 2” Pacer pump is something like 3.5hp, so will be about 2.6kW/h, or about 65p an hour on an average 25p/kWh tariff. Say 20 hours of pumping per 15,000L batch (I turn it off before bed), totals £13 or less than £1 per cube. Please check the maths, I may be wrong.
One thing to note is to use ‘eductors’ (venturis) which increase the volume of pumped water by a factor of 5, so 400L/minute from the pump moves more like 2000L of solution.

Eductors are very good and do improve work very well and yes I am trying to find them for the right money. To add to the set up. But with the paddle it costs approx 30p per m^3 for the mixing and that’s in an less than ideal tank as it’s insulated

 

[Lothian]

It's actually quite easy to mix your own, our set up is a bit mickey mouse compared to some of the ones on here but basically a £150 230v pump from machine mart with some 2" sprayer suction hose and a 10,000l plastic open top tank. Takes us about 2 days to mix a batch so looking to speed this up with some venturi jets and maybe a 2nd pump. Savings have been very good compared to bought in liquid N although you do have to drag a bit of water about. For a bit of extra agitation I also have a small air compressor with the line attached to a steel pole. If you get any stuff settling on the bottom you can use this to agitate it easily.